Melanin provides protection against excess exposure to solar ultraviolet radiation (UVR) and related adverse health effects. Diffuse reflectance spectroscopy (DRS) can be used to calculate cutaneous melanin and erythema, but this is complex and has been mostly used for light-to-medium pigmented skin. Handheld reflectance spectrophotometers, such as the Mexameter® MX18, can also be used. We compared DRS-calculated melanin and erythema values with Mexameter melanin and erythema index values to understand how these techniques/measurements correlate in an African population of predominantly deeply pigmented skin. Five hundred and three participants comprised 68.5% self-identified Black African, 9.9% Indian/Asian, 18.4% White and 2.9% Colored. The majority of Black African (45%), Indian/Asian (34%) and Colored (53%) participants self-identified their skin as being “brown.” Measured melanin levels increased with darker self-reported skin color. DRS-calculated and Mexameter melanin values demonstrated a positive correlation (Spearman rho = 0.87, P < 0.001). The results from both instruments showed erythema values were strongly correlated with their own melanin values. This finding is considered spurious and may result from the complexity of separating brown and red pigment when using narrowband reflectance techniques. Further work is needed to understand melanin, erythema and color in Black skin given sun-related health risks in vulnerable groups in Africa.
|Number of pages||5|
|Journal||Photochemistry and Photobiology|
|Publication status||Published - 1 Jul 2016|
Bibliographical noteFunding Information:
This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. NSF DGE-1144153 to M Wilkes and an international travel allowance co-funded through the Graduate Research Opportunities Worldwide (GROW) and United States Agency for International Development Agencies. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. Dr Wright received support for this project from Council for Scientific and Industrial Research Parliamentary Grant funding, the National Research Foundation Rated Researcher funding and the Cancer Association of South Africa ad hoc grant. We acknowledge the participants for taking part in this study. We thank Mr Bafana Moya, Ms Riëtha Oosthuizen and Ms Victoria Nurse for assisting with data collection.
© 2016 The American Society of Photobiology